1. Field of the Invention
The present invention is directed to the field of graphical displays of database information. It is more particularly directed to efficiently modifying the graphical display of a typically large number of data objects.
2. Description of the Background Art
A computer-implemented database is a collection of data, organized in the form of tables. A table typically consists of columns that represent data of the same nature, and records that represent specific instances of data associated with the table. A relational database is a database that may be a set of tables containing information that is manipulated in accordance with the relational model associated with the data. The product marketed under the trademarks IBM DB2 stores the data associated with the database in tables, and each table has a name.
On-Line Analytical Processing (OLAP) is a computing technique for summarizing, consolidating, viewing, analyzing, applying formulae to, and synthesizing data according to multiple dimensions. OLAP software enables users, such as analysts, managers, and executives, to gain insight into performance of an enterprise, such as a corporation, through rapid access to a wide variety of data dimensions that are organized to reflect the multidimensional nature of enterprise data, typically by means of hypotheses about possible trends in the data. More particularly, OLAP techniques may be used to analyze data from different viewpoints by identifying interesting associations in the information in a database. Therefore, OLAP is a decision support technique used in data management for the purpose of modeling and analyzing business information.
An increasingly popular data model for OLAP applications is the multidimensional database (MDDB). Often, data analysts use MDDBs during interactive exploration of business data for finding regions of anomalies in the data. Before this data can be explored, modeling needs to be enabled for the business. Modeling a business for an OLAP application may require typically large amounts of metadata including data entities.
In the past graphics tools have used objects, such as rectangle displays, to represent data entities, such as relational database tables and OLAP data. The objects are displayed so that they present the relationships between the data contained in the relational database tables and between the OLAP data. It is useful to represent these data entities with as much contextual information as possible to enhance the presentation of the data for use in data modeling and analysis. Given the large amount of OLAP data associated with databases, such as multidimensional databases and relational databases, there may be many objects in the graphical representation. Further, the objects may be manipulated by techniques such as enlarging, minimizing, and moving the objects within the graphical display during creation and manipulation of the business data model. Some of the problems caused by object manipulation during the analysis of the data entities in a graphical display are that representations of the objects may be obscured or difficult to read, and that the contextual reference of the objects may be lost.
For example, scrolling of the graphical display windows typically associated with the presentation of the objects allows other objects to be viewed but has the disadvantage of losing the contextual reference for some of the objects. That is, during scrolling some of the objects may not be visible to the user, thereby losing the contextual reference of those objects. Also, zooming out operations to enable viewing of more objects in the graphical display typically results in the indiscriminate reduction in the size of individual objects. This has the disadvantage that the text within the individual objects is typically rendered too small to read so that the user must repeatedly zoom in to see details of the objects and zoom out to view the contextual relationship of the objects.
Yet another example of the difficulty of managing the graphical display of a large number of data entities occurs when the user is allowed to move the objects thereby enabling flexibility in graphical display but having the disadvantage that the user must constantly reposition the objects as they are expanded and minimized. For example, when a large number of objects are moved, typically one or more of the moved objects obscures the display of other objects thereby reducing contextual information on the graphical display. This type of operation also may require the user to iteratively expand and minimize objects to maintain the information about the contextual relationship of the moved objects.
It would therefore be useful to be able to efficiently analyze typically large amounts of entity information with a graphical display that retains all or most of the relevant contextual information and minimizes distortion of the graphical display. More particularly, when employing OLAP processing techniques that manipulate objects it would be useful to be able to efficiently analyze multidimensional data with a graphical display that minimizes the disadvantages associated with current graphical displays. From the foregoing it will be apparent that there is still a need to improve the graphical display of a typically large number of objects to retain contextual information and minimize graphical display distortion thereby enhancing analysis of the objects and the associated data by techniques such as data mining of relational database information and OLAP data.